Dragline bucket



Sept. 22, 1959 v. LARsEN 2,904,907

DRAGLINE BUCKET Filed March 21, 1955 I VENTOR.

ATTORNE United States Patent DRAGLINE BUCKET Paul Vernon Larsen, Portland, Oreg., assignor to Electric Steel Foundry Company, Portland, Greg, :1 corporation of Oregon Application March 21, 1955, Serial No. 495,395

4 Claims. (Cl. 37135) This invention relates to dragline buckets and the like, and more especially to the spreader bar assembly for such buckets.

In bucket structures, dragline buckets for example, the bucket is ordinarily connected to the hoist cable through a pair of lower hoist chains pivotally secured respectively to opposite side walls of the bucket, and a pair of upper hoist chains that are secured at their upper end to a hoist block and at their lower ends are coupled to the lower hoist chains. A spreader bar provides the coupling for the upper and lower hoist chains, and extends transversely across the bucket and between the pairs of hoist chains. The spreader bar serves to space the lower hoist chains from the side walls of the bucket to prevent binding therebetween.

Dragline buckets are massive structures and weigh many thousands. of pounds when unloaded. Further, they are subjected to rigorous use and not only must be capable of carrying heavy loads, but must withstand impact forces of considerable magnitude. As a result, the spreader bars of such buckets are large and heavy, and in large size buckets may have a weight of several thousand pounds.

Heretofore in buckets of such size, the spreader bars have been connected to the hoist'chains at a plurality of points with the result that bending moments in the bar have been increased, which necessitated the use of even stronger and more massive bars capable of resisting the greater bending moments. A way has now been discovered to connect the upper and lower hoist chains to the spreader bar so as to decrease the bending moment therein, and this is one of the objects of the invention.

Another object of the invention is to reduce the bending moment in a spreader bar structure by connecting the upper and lower hoist chains thereto along the center line of the bar with the result that a lighter weight bar and less costly bar can be employed. Still a further object is to provide a spreader bar structure equipped with bifurcated ends and having a pin extending between the spaced legs of each bifurcated end, a shackle p-ivotally carried by each pin being connected to the upper hoist chains, and the first links in the lower hoist chains being also pivotally carried by the respective pins.

A further object of the invention is in the provision of a spreader bar structure of the character described wherein the pins are equipped with a square head at one end that is received within a square-shaped mating opening in one of the legs of each bifurcated end portion of the spreader bar; the corner portions of the square heads either bearing against a wall portion of the leg to prevent longitudinal movement of the pins in one direction or preferably against a shackle located between each pair of legs, and the pins being locked against longitudinal movement in the opposite direction by plates removably secured to the leg of the spreader bar at each end thereof. Additional objects and advantages will appear as the specification proceeds.

An embodiment of the invention is illustrated in the accompanying drawing, wherein Figure l is a perspective view of a dragline bucket equipped with a spreader bar embodying the invention; Figure 2 is a top plan view of the spreader bar with one end portion thereof being shown in longitudinal section; Figure 3 is a side view in elevation of the spreader bar with one end portion thereof being partially shown in longitudinal section; and Figure 4 is a perspective view of one of the pins.

Reference will firs-t be made to Figure l which illustrates a dragline bucket that is designated generally with the numeral 10. The bucket is equipped with side walls 11 and 12 and with a bottom wall having a plurality of teeth or points 13 projecting forwardly therefrom. Dragline chains 14. are connected to the side walls 11 and 12 at the forward ends thereof, and extending upwardly from the side walls are the lower hoist chains 15 and 16. A spreader bar structure 17 extends transversely across the bucket 19 and between the lower hoist chains 15 and 16. Extending upwardly from the spreader bar 17 are a pair of upper hoist chains 18 and 19 that at their upper ends are connected to a hoist block 20. A hoist cable 21 is connected to the block 2t), and a cable 22 is entrained about the sheave in the block 20 and is connected to the arch 23 of the bucket.

The dragline bucket 10 and the associated structure described may be substantially conventional, and the cables 21 and 22 and the dragline chains 14 may be manipulated in a conventional manner to fill the bucket with a load, transport the loaded bucket to a suitable location and dump the bucket to spill out the load there from. As is well known, the lower hoist chains 15 and 16 are connected to the side wall 11 and 12 of the bucket at an off-center location so that the bucket can be pivoted about the lower ends of the hoist chains 15 and 16 to dump the bucket. The spreader bar 17 performsv the function of spacing the hoist chains 15 and 16 from the side walls of the bucket so that during bucket manipula tion, and especially dumping thereof, there is no binding between the lower hoist chains and walls of the bucket,

etc.

Referring now to Figure 2, it isv seen that the spreader bar 17' comprises a central section 24 that is tubular, and end portions 25 and 26 that may be secured to the central tubular section 24 in any suitable manner. In the illustration given, the end sections 25 and 26. are rigidly united to the central section 24 by welding. To properly locate the end sections 25 and 26 relative to the central section 24, I provide a plurality of equally spaced-apart circumferentially disposed key elements or stops 27 that, after welding, are overlaid by weld 2711. For example, the key elements 27 (four of which are employed in the illustration given--two each being seen in the sectional views shown in Figures 2 and 3). can be employed to dispose the axes of the openings 35, 37 and of the pins in a common plane passing through the longitudinal axis of the central section 24. The tubular section 24 of the spreader bar may be formed from a conventional pipe, and if desired may be made so as to have any other configuration than the tubular form shown. Further, the section 24 might be solid rather than hollow, but ordinarily a hollow section is preferred because of the reduction in weight afforded thereby.

In order to give some indication of the massive character of the spreader bar 17, the outer diameter of the pipe may be greater than 8 /2" and the Wall thickness might be The weight of the pipe section may exceed 500 pounds. Preferably, the end portions 25 and 26 of the spreader bar are cast in the configuration shown.

The end portions 25 and 26 of the spreader bar 17 are bifurcated and have spaced legs 28 and 29, Extend- 3 ing through the legs 28 and 29 provided by each end portion, is a pin 30 that is substantially cylindrical throughout its length but which has a square head 31. Pivotally mounted on each of the pins 30 is a generally U-shaped shackle 32, and the shackle 32 is secured to the first link 33 in each of the upperhoist chains 18 and 19. The legs of the U-shaped shackle 32 are spaced apart, and mounted therebetween and pivotally supported upon the pins 30 are the pear links or first links 34 of the lower hoist chains and 16.

As has been stated before, the pin, at each end of the bar, is cylindrical throughout substantially its entire length, and at one end is received within a round bearing opening 35 extending through the leg 28 of each of the bifurcated spreader bar ends, and at the other end each pin 30 is supported within a square shaped opening 37 in each of the legs 29. The pins are prevented from moving longitudinally in one direction relative to the legs 28 and 29 through engagement with a substantially unyielding member such as bearing surfaces in the legs or, as shown, by abutment with the shackle 32.

The pins 30 are prevented from moving longitudinally in the opposite direction by the hearing or lock plates 38 which slide into covering relation over the heads of the pins through slots or channels provided for that purpose by the fiange elements 39 and 40. These flange elements are effective to inhibit up and down movement of the plates, as viewed in Figure 3, while the enlarged or protruding stop members 41 provided by each of the legs 29 at their ends tend to limit longitudinal movement of the plates in a direction toward the outer ends of the legs. Each plate is rigidly held in position by a cap screw 42 that extends through the plate and is threadedly received within a nut 43 locked within an appropriate bore or counter recess 44 in the leg 29.

In use of the structure, the end portions and 26 of the spreader bar are inserted into the ends of the central section 24 of the spreader bar. A rigid uniting of the end portions with the central section is provided by welding the members together. Welding of the end portions and central section produces a homogeneous bar structure preventing the ends from rotating and further materially aids in enabling the bar to withstand the tremendous shock loads to which it is subjected.

The shackles 32 are threaded through the first links 33 of the upper hoist chains 18 and 19, and the pear links 34 of the lower hoist chains 15 and 16 are positioned between the spaced legs of the U-shaped shackle members. The pins are then inserted through the openings in the legs 29, through the shackle 32 and pear link 34 of each of the hoist chains and into the bearing opening in each of the legs 28 of the bifurcated ends of the spreader bar assembly. The heads 31 are aligned with the mating openings 37 and are pressed thereinto. The lock plates 38 are then moved longitudinally through the recessed flange members 39 and and into the positions shown in Figures 2 and 3. Thereafter, the cap screws 42 are threaded into their respective nuts 43 and are tightened against the plates 38 to lock the same in position.

It is apparent that the upper and lower hoist chains at each side of the bucket 10 are secured to the spreader bar 17 by means of the pins 30. The pins 30 lie along the center line of the spreader bar 17, and all of the forces exerted on the spreader bar 17 are directed thereagainst through the pins 30. Since these pins lie along the center line of the spreader bar, the forces applied thereto act at points along the center line of the bar. Therefore, normal or usual forces transferred to the spreader bar through the upper and lower hoist chains are not eccentrically applied to the spreader bar, and it will be appreciated that bending moments are thereby decreased. As a result, there is no increase through eccentric loading of the forces that result from use of the dragline bucket, and it is found that the elimination of such forces is a substantial contribution and permits the use of a less massive spreader a bar, and that, of course, is accompanied by a decrease in the cost of spreader bar structures.

While in the foregoing specification an embodiment of the invention has been elaborated in considerable detail for purposes of adequately describing the invention, it will be apparent to those skilled in the art that numerous changes may be made in the details set forth without departing from the spirit and principles of the invention.

I claim:

1. In a structure of the character described for use with dragline bucket assemblies, a spreader bar comprising an elongated hollow midsection equipped at each end with a casting, each casting having a pair of spacedapart legs equipped with aligned openings lying on the longitudinal axis of said bar, a pin extending through the openings in each pair of legs of each casting, said pins providing a pivotal connection for upper and lower hoist chains, one of said legs on each end casting being provided with a channel having one open end and communicating with the opening in its leg, a plate mounted within each channel and being confined therein by the walls of the channel, and fastener means extending through each plate and into the leg of each end casting to removably secure the plate thereto,'each plate abutting the pin in the end casting thereof to preventing movement of the pin in one direction.

2. A structure according'to claim l,'in which each of said castings is provided with a plurality of equally spaced-apart key elements extending longitudinally inwardly and received within said hollow midsection.

3. In a structure of the character described, an elongated spreader bar equipped at each end with spacedapart legs having aligned openings extending therethrough, said openings lying along the center line of the spreader bar structure, a pin extending between each pair of spaced-apart legs and being received within the openings provided thereby, a generally U-shaped shackle having leg portions positioned between the spaced legs at each end of the spreader bar structure and being pivotally mounted upon the respective pins, each of said shackles extending generally upwardly from said spreader bar structure, upper hoist chains connected to said shackles, lower hoist chains at each end of said spreader bar structure and having a first link received between the legs of each of said U-shaped shackles and being pivotally carried on the respective pins, each of said pins havinga generally square-shaped head and one of said legs at each end of the spreaderbar being provided with a channel open at one end communicating with the opening in said leg, said square-shaped head being completely received in said opening, a plate in each of said channels in abutment with the square-shaped head of the pinand. being confined by the walls of the channel, and fastener means for securing each plate in its channel.

4. In a structure of the character described, an elongated spreader bar equipped at each end with spacedapart legs having aligned openings extending therethrough, said openings lying along the center line of the spreader bar structure, a pin extending between each pair of spacedapart legs and being received withinthe openings provided thereby, a generally U-shaped shackle having leg portions positioned between the spaced legs at each end of said spreader bar structure and being pivotally mounted upon the respective pins, each of said shackles extending generally upwardly from said spreader bar structure, upper hoist chains connected to said shackles, lower hoist chains at each end of 'said spreader bar structure and having a first link received between the legs of each of said U-shaped shackles and being pivotally carried upon the respective pins, each of said pins being provided with an enlarged head and one leg of each of said pair of legs being equipped with a longitudinally-extending channel communicating with the opening in said leg, the enlarged head of the pin associated with said leg being Completely received in said opening, and plate means 5 6 secured in each of said channels abutting the said en- 1,808,311 Madonna June 2, 1931 larged head. 1,834,391 Edmunds Dec. 1, 1931 1,882,147 Humphreys et a1. Oct. 11, 1932 References Cited 1n the file of thls patent 2,001,924 Strong May 21 1935 UNITED STATES PATENTS 5 2,181,125 Eckart Nov. 28, 1939 483,221 'Hunt et a1. Sept. 27, 1892 

